Metronome



NOV. 19, '1940. s, Q HOWARD ET AL 2,222,032

` METRONOME Filed Dec. l2, 1939 2 Sheets-Sheet l omeys Nov. 19, 1940.

s. C. HOWARD ET AL 2,-'2-'7--2Q032` METRONOME Filed Dec. l2, 1959 2 Sheets-Sheet 2 Inventors Patented Nov. 19, 1940 UNITED STATES PATENT OFFICE METRONOME Application December 12, 1939, Serial No. 308,878

1 Claim.-

Our invention relates to improvements in metronomes and the principal object in View is to provide an inexpensive device of this character operative by clock-works and invariable as 5 regards timing so that it may be manufactured as a precision instrument adjusted to beat a set tempo.

To the accomplishment of the above and subordinate objects presently appearing, a preferred embodiment of our invention has been illustrated in the accompanying drawings, set forth in detail in the succeeding description, and defined in the claim appended hereto.

In said drawings:

Figure l is a view in front elevation of the preferred embodiment of our invention,

Figure 2 is a similar view the cover section of the casing removed,

Figure 3 is a fragmentary view in front elevation of the clock-Works removed,

Figure 4 is a View in side elevation of the signal carrier and flash plate,

Figure 5 is a view in rear elevation of said carrier and plate, and

Figure 6 is a View in edge elevation of the plate.

Referring to the drawings by numerals, the metronome ci' our invention comprises a flat rectangular casing I including a main, open front, back section 2, and a iront cover section 3 which may be detachably secured to section in any suitable manner as, for instance, by fitting over the same.

The back section 2 has suitably secured therein, in centered relation thereto, as by screws 4,

the frame 5 of a clock-works 6, said frame being arranged upright andthe clock-Works being of the type embodying an escapement wheel l adjacent to the bottom of the frame 5, an escapement controlling fork 8 mounted for vertical oscillation in a xed bearing sleeve 9 on the frame 5, and a balance wheel ID coacting with said fork and having attached thereto the usual hair spring, as at iii. The escapement wheel 'I controls the reaction of the usual winding spring II through the usual train of gearing designated as a unit, by

the numeral I2.

According to our invention, the escapement controlling fork 8 is provided With an integral axis arbor i3 extending through the sleeve bearing 9 and the iront of the frame 5, and a right angled upright arm forming an integral extension of said arbor I3 and constituting a signal carrier I4 vibrated between the frame 5 and the cover section 3 under oscillation of the arbor I3. The upper end of the signal carrier I4 has attached thereto a rectangular, upright iiash plate I5 preferably attached to said carrier by means of a rolled edge I6 on the plate sleeved onto and suitably secured to said carrier to be vibrated thereby in a plane parallel with the 5 iront face of the cover section 3.

A rectangular sight opening Il is provided in the front face of the cover section 3 past which the signal plate I5 is vibrated and which is located a-t either limit of vibratory movement of 10 said plate. The signal plate I5 may be distinctively colored if desired in contrast to the cover section 3 to render the same readily visible to the eye.

At the angle oi juncture of the arbor I3 and 15 right angled arm or signal carrier I4 a counter- Weight i8 is preferably although not necessarily provided for counterbalancing said carrier and the plate l5.

The operation of the described invention will 20 be readily understood. As the escapement controlling fork 8 oscillates, the arbor I3 is similarly operated to vibrate the signal carrier I4 and the signal plate i5 thereby moving the latter into registration with the sight opening I'I to 25 flash a signal at each stroke of said escapement controlling fork 8. Since the escapement controlling fork 8 vis timed as regards oscillation by v the hair-spring of the balance wheel I0, the signal ilashed by the plate I5 is similarly timed. 30 Thus the timing of the signal is xed in the device, that is to say, inherent in its structure, so as to indicate, or beat, a constant xed tempo and such timing cannot be varied without increasing or shortening the length of Ithe hair- 35 spring. By virtue of this arrangement each device may be manufactured to beat a xed tempo of different timing by varying the length of the hair-spring embodied in the structure.

The foregoing will, it is believed, suice to im- 40 part a clear understanding of our invention without further explanation.

Manifestly the invention, as described, is susceptible of modification without departing from the inventive concept and right is herein re- 45 served to such modications as fall within the scope of the subjoined claim.

What we claim is:

In a device of the class described, a casing having a front wall provided with a sight opening 50 therein, a signal plate adapted to be vibrated in the rear of said opening for intermittent display therethrough, and means to vibrate said plate and to invariably time the vibration thereof comprising a clock-works in said casing includ- 55 ing an oscillating esoapement fork having a 'lxed arbor thereon providing an axis of oscillation therefor, means to invariably time oscillation of said fork, and a plate carrying arm for vibrating said plate forming an integral extension of said arbor whereby vibration of said plate is timed in correspondence with timing of said fork and by said timing means, said arm extending upwardly at substantially 90 degrees from said arbor, and a counterweight at the juncture of said arbor and arm, said sight opening being disposed at one limit of vibratory movement of said plate.

SIDNEY C. HOWARD. BERT WILLIAMS. 

